The present invention relates to a cushioning support member for housing and supporting contents and a fabricating method thereof. In particular, the present invention relates to a cushioning support member which is formed from a single piece of corrugated cardboard and a fabricating method thereof.
Conventionally, a packaging container used for a comparatively small-sized electronic equipment shown in FIG. 1 is generally known. FIG. 1 is a development of the packaging container 1, and four side surface portions 2a through 2d which form a square cylindrical main body are connected in a lateral direction via three fold lines 3a through 3c. A paste margin 2e is connected to the outside of the fourth side surface portion 2d via a fourth fold line 3d. 
A first connecting portion 4a is connected to the lower side of the side surface portion 2a via a fifth fold line 3e, and a first bottom portion 5a is connected to the lower side of the side surface portion 2b via a sixth fold line 3f. Moreover, a second connecting portion 4b is connected to the lower side of the side surface portion 2c via a seventh fold line 3g, and a second bottom portion 5b is connected to the lower side of the side surface portion 2d via an eighth fold line 3h. A first holding portion 6a is connected to the upper side of the side surface portion 2a via a ninth fold line 3i, a first upper surface portion 7a is connected to the upper side of the side surface portion 2b via a tenth fold line 3j. Moreover, a second holding portion 6b is connected to the upper side of the side surface portion 2c via an eleventh fold line 3k, and a second upper surface portion 7b is connected to the upper side of the side surface portion 2d via a twelfth fold line 3l. Further, a first insertion portion 8a is connected to the first upper surface portion 7a via a thirteenth fold line 3m, and a second insertion portion 8b is connected to the second upper surface portion 7b via a fourteenth fold line 3n. 
As for the packaging container 1 constituted in the above manner, the paste margin 2e is overlapped with the first side surface portion 2a and are sealed by adhesive so that a cylindrical main body which forms a square frame is formed. An end closing portion which closes a lower end of the cylindrical main body is composed of the two bottom surface portions 5a and 5b. The two bottom surface portions 5a and 5b have trapezoidal shapes of equal shape and size which become narrower towards their ends. Engagement portions 9a and 9b for engaging the ends of the bottom surface portions 5a and 5b with each other so as to make them self-locking are provided respectively at the center portions of the ends.
One edge of the engagement portions 9a and 9b of the bottom surface portions 5a and 5b is a circular convex portion, and the other edge is an inclined portion with an angle of about 45xc2x0. First and second coupling portions 11a and 11b are provided via first and second hollow fold lines 10a and 10b which extend slantingly from the bottoms of the inclined portions towards the directions of the first and third fold lines 3a and 3c. The coupling portions 11a and 11b are overlapped with the first and second connecting portions 4a and 4b respectively so as to be sealed by adhesive. As a result, the first connecting portion 4a is jointed to the first bottom portion 5a, and the second connecting portion 4b is jointed to the second bottom surface portion 5b. Meanwhile, the engagement portion 9a of the bottom surface portion 5a is engaged with the engagement portion 9b of the other bottom surface portion 5b so that the bottom surface which is the self-locking type end closing portion is formed.
As a packaging cushioning material which is used for the packaging container 1, a cushioning material made of plastic foam such as styrene foam or obtained by pulp molding is generally used. However, as the cushioning material using a corrugated cardboard, a cushioning material shown in FIGS. 2 and 3 is known, for example. The cushioning material 12 made of corrugated cardboard has an inside cushioning portion 13 and an outside cushioning portion 14 which are cut out of one piece of corrugated cardboard and are arranged parallel with each other. The cushioning portions 13 and 14 are connected by a connecting portion 15 at their center portions so as to form a united piece of material. The cushioning portions 13 and 14 are bent along first and second fold lines 16a and 16b which are provided respectively on both sides of the connecting portion 15 so that the inside cushioning portion 13 which is slightly shorter is overlapped on the outside cushioning portion 14.
The inside cushioning portion 13 has a first inside portion 13a and a second inside portion 13b which are connected via third and fourth fold lines 16c and 16d, and a third inside portion 13c which is connected via a fifth fold line 16e. One side of the connecting portion 15 is connected to the second inside portion 13b positioned in the center portion. The outside cushioning portion 14 has a first outside portion 14a and a second outside portion 14b which are connected via sixth and seventh fold lines 16f and 16g and a third outside portion 14c which is connected via eighth and ninth fold lines 16h and 16i. The other side of the connecting portion 15 is connected to the second outside portion 14b positioned at the center portion. An engagement portion 14d is connected to the first outside portion 14a via a tenth fold line 16j, and two fold lines 16k and 16l are provided to the engagement portion 14d. 
Furthermore, the first through third inside portions 13a through 13c of the inside cushioning portion 13 and the first and third outside portions 14a and 14c of the outside cushioning portion 14 are provided respectively with housing holes 17a through 17e which form a housing concave portion 17 for housing a content such as electronic equipment. The housing holes 17a through 17e are formed into shapes according to section shapes in each layer of the content by the order of folding the first through third inside portions 13a through 13c and the first and third outside portions 14a and 14c. The first outside portion 14a positioned in the topmost layer is provided with a slip-off preventing portion 18 which covers a portion of a peripheral edge of the content so as to prevent the content from slipping out of the housing concave portion 17, and a through groove 19 through which a strap or the like attached to the content is inserted.
The cushioning material 12 having such a structure is assembled in the following manner. The inside cushioning portion 13 and the outside cushioning portion 14 are folded along first and second fold lines 16a and 16b so that the inside cushioning portion 13 is overlapped on the outside cushioning portion 14. The third inside portion 13c is folded along the fifth fold line 16e so as to be overlapped on the second inside portion 13b. The first inside portion 13a and the second inside portion 13b are folded long the third and fourth fold lines 16c and 16d so that the first inside portion 13a is overlapped on the third inside portion 13c. The second outside portion 14b and the third outside portion 14c are folded along the eighth and ninth fold lines 16h and 16i so that the third outside portion 14c is overlapped on the first inside portion 13a. Further, the first outside portion 14a and the second outside portion 14b are folded along the sixth and seventh fold lines 16f and 16g so that the first outside portion 14a is overlapped on the third outside portion 14c. The engagement portion 14d is folded along the tenth, eleventh and twelfth fold lines 16j, 16k and 16l successively so as to be twined. As a result, as shown in FIG. 3, the corrugated cardboard-made cushioning material 12 having the six-layered structure can be obtained.
However, in the conventional packaging container, the cushioning material 12 (or cushioning material such as styrene foam) is provided separately from the packaging container 1. The cushioning material 12 is housed in the assembled packaging container 1 and the content is wrapped by the cushioning material 12 so as to be protected. For this reason, a great number of parts are used and this is expensive, and a lot of packaging steps are required. Furthermore, the following problem arises.
In the case where the cushioning material made of styrene foam or the like is used, since the cushioning material is generally fabricated by using a die, it takes a lot of time to fabricate the die and the production costs of the die are large. As a result, the production costs of the die is added to the cushioning material, and the cushioning material itself is expensive. Moreover, in the case where the cushioning material made of styrene foam is used, since the recycle system of used cushioning materials is not established, there arises a problem of the disposal of used materials. Therefore, the cushioning material is not preferable from the viewpoint of the environment.
In the case of the cushioning material 12 obtained by assembling the corrugated cardboard, one surface of the housing concave portion 17 to/from which a content is attached/detached is open. For this reason, it is impossible to cover the housed container wholly by only the cushioning material 12 and protect it. Moreover, a substantially large space in the packaging container 1 is filled with the cushioning material 12 except for a content. For this reason, a lot of corrugated cardboard is used and this is expensive and the weight becomes larger. Further, since the cushioning material 12 is mostly stored with it being assembled as shown in FIG. 3, a wide space for the storage is required, and transport costs increase.
The present invention is devised in order to solve the conventional problems. It is an object of the invention to provide a cushioning support member in which a container pattern which is obtained by cutting out of one corrugated cardboard is folded so as to have a cubic shape so that a content can be held securely and if an external force is applied due to dropping, the external force is absorbed by deformation of the container and the content is not damaged.
A cushioning support member of the present invention comprises: a polygonal bottom surface portion; a plurality of side surface portions formed continuously on respective sides of the bottom surface portion; and a plurality of supporting piece portions which are formed on at least two side surface portions of the plurality of side surface portions, wherein the bottom surface portion, the plurality of side surface portions and the plurality of supporting piece portions are formed by one corrugated cardboard, and the plurality of supporting piece portions, a plurality of supporting column portions, which are formed by bending into a cylindrical shape so as to support four corners of a cubic content, and a plurality of contact portions which contact with side surface of the content are formed, and connecting portions with the plurality of side surface portions are bent so as to support the cubic content.
A method of fabricating a cushioning support member according to the present invention, comprises the steps of: forming a base material, which has a polygonal bottom surface portion, a plurality of side surface portions formed continuously on sides of the bottom surface portion, and a plurality of supporting piece portions formed on at least two side surface portions of the plurality of side surface portions, from one corrugated cardboard; forming the plurality of supporting piece portions, a plurality of supporting column portions which are bent into a cylindrical shape so as to support corner portions of a cubic content, and a plurality of contact portions which contact with side surfaces of the content; and bending continuous portions between the bottom surface portion and the plurality of side surface portions into a substantially box shape.